Apparatus to actuate a downhole tool

Abstract

The invention provides an apparatus for actuating a downhole tool by utilizing a pressure differential created by fluid flowing through a conduit. The conduit is in communication with a pressure sensing line that is selectively exposable to areas of the conduit having different pressures. By exposing the pressure sensing line to a portion of the conduit having a predetermined pressure therein, the pressure sensing line causes actuation of a hydraulic tool therebelow.

What is claimed is:  
     
       1. An apparatus for actuating a downhole tool comprising: 
       a first conduit for flowing fluid therethrough;  
       a pressure sensing line in communication with the first conduit; and  
       the pressure sensing line sensing pressure in the first conduit and communicating a predetermined pressure to an apparatus that actuates the downhole tool while fluid flow is maintained through the first conduit.  
     
     
       2. The apparatus of  claim 1 , where the first conduit includes a pressure changing restriction therein, the restriction creating a greater pressure in the conduit thereabove than therebelow. 
     
     
       3. The apparatus of  claim 2 , wherein the restriction is movable from a first to a second position within the first conduit. 
     
     
       4. The apparatus of  claim 3 , whereby movement of the restriction from the first to the second position exposes the pressure sensing line to the greater pressure. 
     
     
       5. The apparatus of  claim 4 , whereby when the greater pressure reaches a predetermined pressure, the downhole tool is actuated. 
     
     
       6. The apparatus of  claim 2 , wherein the pressure sensing line and the restriction are movable relative to one another. 
     
     
       7. The apparatus of  claim 1 , whereby the first conduit is in fluid communication with a device with one or more orifices that restrict the fluid flow and increase the pressure in the first conduit as the fluid flow is increased. 
     
     
       8. The apparatus of  claim 7 , whereby the device with one or more orifices is a mill. 
     
     
       9. The apparatus of  claim 8 , whereby the downhole tool is actuated when the pressure reaches a predetermined pressure. 
     
     
       10. The apparatus of  claim 7 , whereby the one or more orifices are removable and may be replaced with one or more orifices of different sizes, thereby creating different pressures in the first conduit for a given fluid flow, based on the size and quantity of the one or more orifices. 
     
     
       11. The apparatus of  claim 7 , whereby the pressure sensing line is exposed to the increase in pressure. 
     
     
       12. An apparatus for actuating a downhole tool comprising: 
       a conduit for flowing fluid therethrough;  
       a restriction within the conduit, the fluid having a lower pressure below the restriction and a greater pressure above the restriction, the restriction movable from a first position to a second position within the conduit upon a predetermined increase in the fluid flow therethrough;  
       a pressure sensor in fluid communication at an upper end with the conduit proximate the restriction, the sensor carrying the lower pressure when the restriction is in an upper position and the greater pressure when the restriction is in a lower position; and  
       a piston having a piston surface in fluid communication with a lower end of the pressure sensor, the piston constructed and arranged to move from a first to a second position upon the predetermined increase in the fluid flow through the restriction.  
     
     
       13. The apparatus of  claim 12 , further including a hydraulically operated tool disposed below the apparatus, the hydraulically operated tool actuatable by the movement of the piston to the second position. 
     
     
       14. The apparatus of  claim 13 , wherein the piston further includes a second surface having a projection for puncturing an atmospheric chamber formed within the hydraulically operated tool. 
     
     
       15. The apparatus of  claim 14 , wherein the atmospheric chamber of the hydraulically operated tool is exposed to a borehole pressure by the movement of the piston to the second position, the borehole pressure acting upon a piston surface of the hydraulically operated tool to move a movable member within the tool from a first position to a second position. 
     
     
       16. The apparatus of  claim 13 , wherein the hydraulically operated tool is an anchor and the movable member cooperates with at least one gripping member of the anchor to engage the anchor with a borehole wall. 
     
     
       17. The apparatus of  claim 16 , wherein the hydraulically operated tool further includes a packer and the movable member cooperates with an opposing surface to actuate packer material and seal an annular area around the packer. 
     
     
       18. The apparatus of  claim 12 , further including a cutter disposed below the restriction. 
     
     
       19. The apparatus of  claim 18 , further including a whipstock disposed between the cutter and the piston. 
     
     
       20. A two position, flow through piston assembly for actuating a hydraulically actuated tool in a borehole, the assembly comprising: 
       a housing;  
       a piston member disposed within the housing in a first position;  
       a restriction formed within a piston, the restriction allowing the flow of fluid therethough while creating a higher pressure area thereabove and a lower pressure area therebelow, the piston movable to a second position when the higher pressure is increased to a predetermined level; and  
       a pressure sensor, the first end of which is attached to a body proximate the piston the pressure sensor carrying the lower pressure when the piston is in the first position and the higher pressure when the piston is in the second position, the second end of the pressure sensor attached proximate a hydraulically operated tool and constructed and arranged to actuate the tool when the piton moves to the second position.  
     
     
       21. A hydraulically actuatable downhole tool comprising: 
       an outer body for disposed in a tubular;  
       at least one piston formed within the body having a first and second positions therein; and  
       an atmospheric chamber formed within the tool and creating a pressure differential between the contents of the chamber and a borehole pressure, the chamber having a rupture disk at an upper end thereof; whereby when the rupture disk fails, the pressure differential causes the at least one piston to move to the second position, thereby actuating the tool.  
     
     
       22. The tool of  claim 21 , wherein the tool is a hanger and includes at least one gripping member that is set by movement of the at least one piston. 
     
     
       23. The tool of  claim 21 , wherein the tool is a packer with an expandable portion that is set by the movement of the at least one piston. 
     
     
       24. A method of  claim 21 , wherein the rupture disk is ruptured by an explosive device located proximate the rupture disk and controlled by an electrical signal. 
     
     
       25. A method of setting a hydraulically-actuatable mechanism and commencing drilling in a single trip of a drill string comprising the steps of: 
       assembling a drill string having a MWD subassembly capable of detecting downhole parameters and communicating the detected data to the surface of the borehole, a pressure sensing line for actuating the hydraulically-actuatable mechanism;  
       running the assembled drill string in the borehole and positioning the hydraulically-actuatable mechanism at a predetermined location;  
       sensing the orientation of the drill string using the MWD subassembly;  
       orienting the drill string in the desired orientation;  
       changing the pressure in the drill string whereby the pressure sensing line sets the hydraulically-actuatable mechanism while flow is maintained through the MWD subassembly; and  
       lowering and rotating the drill string to release a cutter assembly from the hydraulically-actuatable mechanism and to commence drilling.  
     
     
       26. A method of setting a hydraulically-actuatable mechanism and commencing drilling in a single trip of a drill string comprising the steps of: 
       assembling a drill string having a MWD subassembly capable of detecting downhole parameters and communicating the detected data to the surface of the borehole, a pressure sensing line in fluid communication with the drill string and a hydraulically-actuatable mechanism while the flow of fluid is maintained through the drill string, a cutter assembly and the hydraulically-actuatable mechanism;  
       running the assembled drill string in the borehole and positioning the hydraulically-actuatable mechanism at a predetermined location;  
       sensing the orientation of the drill string using the MWD subassembly; orienting the drill string in the desired orientation;  
       exerting a fluid pressure through the drill string to set the hydraulically-actuatable mechanism;  
       lowering and rotating the drill string to release the cutter assembly from the hydraulically-actuatable mechanism and to commence drilling.